This has probably been answered...

The first part of the Cloaking Device upgrade says "Action: Perform a free cloak action"

Where would you perform your closk action, during the Perform Action Step?

And if so, are you still able to take another action?

Yes; and

No.

(In that order. )

Even tho it says free action?

The wording is confusing but specific. If it said "Action: Perform a cloak action" then you would require a way of taking two actions in order to do it. Expert Handling is worded the same.

Furelli

The card has an action header.

This indicates you can perform the text on the card as your standard action or as the free action granted by Experimental Interface or other card abilities.

This action then let's you perform a free cloak action. This is a common card design. You already spent an action to activate the card, so it has to grant you a specific free action in order for you to do that action , perhaps even combined with other effects.